We are using membrane glycoproteins of envelopes viruses to investigate the mechanisms by which eurkaryotic cells direct proteins to various cellular compartments. Biochemical, genetic and recombinant DNA methods will be used to identify structural features of viral glycoproteins that determine their intracellular migration processes, and ultrastructural studies will be used to identify the cellular site at which glycoproteins are sorted into different membranes. We will further characterize the glycosylation sites and oligosaccharide chains of antigenic variants of influenza A viruses in an effort to understand the possible role of glycosylation in antigenic variation. Inhibitors of glycosylation will also be used to investigate the role of carbohydrates in the structure and biological and antigenic properities of the influenza A hemagglutinin glycoproteins. We will determine the primary structure of the glycoprotein of influenza C viruses, which differs from the hemagglutinin of influenza A and B viruses in structure and biological activities. The morphology of this glycoprotein and its arrangement on the viral envelope will be further investigated in electron microscopic studies.